The invention relates to light diffusers.
In a fluorescent lamp, phosphor crystals are coated on the inner surface of a glass envelope containing a mercury vapor. The lamp includes a cathode for generating electrons which bombard the vapor and generate ultraviolet light. The ultraviolet light causes the phosphor crystals to emit visible light in both radial and tangential directions of the glass envelope. Because it is generally desired that the light be directed to particular areas, reflectors are generally used to help direct the emitted light to the target areas.
A typical fluorescent lighting system, for example, has a housing, referred to as a troffer for supporting one or more fluorescent tubular lamps, as well the necessary wiring and electrical hardware for providing power to the lamps. The troffer generally has a box-like structure and is often used as a reflector. Light rays incident on the side and rear portions of the troffer are either absorbed or reflected by the surface. The inner surfaces of the troffer are typically painted white in order to decrease the amount of light absorbed by the surfaces.
With rising energy costs, efforts are being made to improve the optical efficiency of lighting systems. The optical efficiency represents the total amount of light directed to an area relative to the total amount of light generated by the lamp.